Platen press for the working of blanks, such as cardboard blanks



July 11, 1544. H. BOB-ST ET AL 2,353,215

PLATEN-PRESS FOR THE WORKING OF BLANKS, SUCH AS CARDBOARD BLANKS Filed Sept. 17, 1941 .9 L \X/ YY E r p 6" 1 I 5 2 4 2 INVENTORS.

fl TTORNEYS Patented July 11, 1944 PLATEN. PRESS FOR WORKING OF BLANKS, SUCH AS CARDBOARD BLANKS 'Henri Bobst and Josef Kiiry, Lausanne, Switzerland, 'as'signors to J. Bobst 8: Fils S. 'A.,-Prilly, Switzerland, a corporation of Switzerland Application September 17, 1941, Serial No. 411,145 In Switzerland October 9, 1940 2 Claims.

The present invention relates to a platen-press for the working of blanks in particular cardboard blanks that are conveyed to and from the platen by gripper-bars disposed between endless chains.

In the usual known platen-presses with or with out carrying chains, the blanks travel between the side-parts of the press-frame which obstructs both sides so that the platens are only accessible at the points where the blanks enter and leave therefrom. The introducing, withdrawing, registering and watching of the tools can take place consequently only at these two places and entail each time the removal of a few elements of the press.

An object of the invention is to facilitate greatly the introduction, withdrawing, registering and watching of the tools, as will be hereinafter described and pointed out in the claims.

To assist in explaining the invention, the accompanying drawing has been provided which serves to illustrate the same as follows:

Fig. 1 is a cross-section of the platen and of a chain parallel to a gripper-bar, this figure showing only half of a press.

Fig. 2 is a diagrammatic view of two gripperbars carrying blanks and of the pressing tools situated below.

Fig. 3 shows a detail of Fig. l on a larger scale.

The press shown in Fig. 1 has a frame of which a lateral standard I is shown in cross-section.

The upper and lower platens are designated by 2 and 3, respectively. The first one is fixed, while the second one is movable up and down by means of toggle-levers 4.

There is a tool on the upper platen fixed upon the tool supporting frame 5, and on the lower platen is a presser-tool 6.

At I one of the chains is shown in cross-section. It carries gripper-bars (not shown) travelling between the tools and connecting said chain with a second symmetrically disposed chain (not shown on the left). Both chains are moved together and intermittently.

The position of the platen shown corresponds to the inactive dead-point of the latter, i. e. the movable platen 3 occupies its lowest position and the distance between both platens is the greatest possible.

As may be seen, the conditions are such that the working-tools as well as the pressing-tools can be withdrawn sideways, in a direction across the direction of travel of chains 1, the said tools sliding for this purpose along the platen-surfaces.

The positions 5 and 6 show in dots and dashlines how to slide them out. This is possible, due

to an orifice passage 8 made in the lateral standard I and extending in the direction of the chain.

Further, guides 9 are provided in the said standard which in the considered dead-point position of the tools lie opposite said tools in such a way as to permit said tools to slide directly along the said guides in order to be supported like an overhanging girder. Therefore the controlling of the pressing-tools as well as of the working-tools can be done without the necessity of taking the same completely out of the press and putting them down elsewhere.

The tools can also be taken off the said press while it is working, and it is not necessary to stop the press. The diagram of Fig. 2 shows how this is possible. When the platens are at their greatest distance apart, two gripper-bars such as H], II, always attain the shown positions in which the blanks [2, I3, resting on leaving guide l4 and on the introducing guide [5, will not interfere with the removal of the pressing-tools 6.

In consequence of the high working pressure of the press, the tools often stick so tightly to the platen that it is hard to loosen them. A device according to Fig. 3 can be used to loosen them as well as to fix them. Such a device as shown is applied to the presser-tools and facilitates the unloosening of the same from platen 3.

A hollow sleeve I6 is fixed on the presser-tool, and contains a spring I! sealed between a collar 2| on the plunger and the end of the hollow sleeve, pushing a plunger l8 out of said sleeve. The plunger ends with a screw-thread l9 and is rotatable by means of a handle 2|], in order to be screwed in a correspondingly threaded cavity in platen 3.

By screwing this bar out, the spring I! will be compressed as the screw-threaded part goes back while the sleeve l6 screwed in with the pressen-tools 6 still remain immovable. The spring will be compressed until the accumulated energy pushes the sleeve l6 and presser-tools 6 outwardly and loosens the said tools from the platen.

With the reintroducing of the presser-tools 5 the screw-threaded part I9 is screwed again on the suitable thread of the platen 3 ensuring the complete registering of the said tools.

The possibility of the withdrawal of bar l8 against the action of spring I! gives a new advantage. If the tools 6 are put too roughly into the press, the impact of the part I9 of the plunger l8 against the corresponding part of the platen is cushioned so that the thread cannot be harmed.

As the withdrawing of both tools must and can only take place when the distance is the greatest between the platens, the press can be fitted up with control devices, for example with a lamp which lights up when the intended position is reached, or safety means which prevents the starting of the press when the tools are not placed rightly.

What we claim is:

1. In a press for Working cardboard blanks and the like having platens one of which is movable towards and from the other and a blank working tool movable into and out of position between said platens, the provision of means for securing said tool in proper relation to said platens and for facilitating its removal from between said platens, said means comprising an interiorly threaded cavity in one of said platens, a hollow sleeve having a part fixedly connected to said tool, a plunger in said sleeve having an exteriorly threaded extremity engageable with the interiorly threaded cavity in said platen, a collar on said plunger and a spring arranged between said collar and the end of said sleeve and adapted to b compressed upon unscrewing movement of said plunger.

2. A device as claimed in claim 1, having means for rotating said plunger for bringing its threaded portion into and out of engagement with said threaded cavity.

HENRI BQBST. JOSEF KURY. 

